Segment Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2021 segment	Dec. 31, 2021	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments		2	2
Revenues
Total Operating Revenue	$ 1,948,526			$ 1,742,101	$ 1,707,361
Operating Income (Loss)
Total Operating Income	18,429			43,551	26,070
UNITED STATES
Revenues
Total Operating Revenue	1,948,526			1,742,101	1,704,989
MEXICO
Revenues
Total Operating Revenue					2,372
Truckload Segment [Member]
Revenues
Total Operating Revenue	1,567,520			1,513,276	1,521,494
Operating Income (Loss)
Total Operating Income	15,323			56,267	24,071
Brokerage Segment [Member]
Revenues
Total Operating Revenue	381,006			228,825	185,867
Operating Income (Loss)
Total Operating Income	$ 3,106			$ (12,716)	$ 1,999